Concrete mixer



Jan. 24, 1956 c. GERsT 2,732,189

CONCRETE MIXER Filed Dec. 5, 1952 6 Sheets-Sheet l N w `o N o 4 /.-/i n o NM Q W QM *L N N P Rg *i k l T1 N Q 0% N sw I w Jaw N S 1 ITVVENTOR.

Jan. 24, 1956 c. GERsT 2,732,189

CONCRETE MIXER l Filed Dec. 5, 1952 e sheets-sheet 2 6 Sheets-Sheet 3 C. GERST CONCRETE MIXER Jan. 24, 1956 Filed Dec. 5, 1952 y ma Nm. .s Z ,W A a y/ B SQ W%\ W www Jan. 24, 1956 c. GERS-r 2,732,189

CONCRETE MIXER Filed Dec. 5, 1952 6 Sheets-Sheet 4 I INVENTOR. 5g/'Z s 6,6/5

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c. GERsT CONCRETE MIXER Jan. 24, 1956 6 Sheets-Sheet 5 Filed Dec. 5, 1952 I INVENTOR. '/ZS @ens-Zt. E? Z v Jan. 24, 1956 Filed Dec. 5, 1952 C. GERST CONCRETE MIXER 6 Sheets-Sheet 6 INVENTOR.

United States Patent O CONCRETE MIXER Chris Gerst, Detroit, Mich., assig'nor, by mesne assignments, to Westinghouse Air Brake Company, a corporation of Pennsylvania Application December 5, 1952, Serial No. 324,370

13 Claims. (Cl. 259-177) This invention relates to concrete mixers and has particular reference to certain new and useful improvements pertaining to driving and supporting means for concrete mixers of the transit type.

A principal object of the invention is to provide a new and improved construction for concrete mixers of the transit type.

Another object of the invention is to provide a new and improved supporting and driving arrangement for mixer drums of concrete mixers.

Another object of the invention is to provide a supporting arrangement for mixer drums of transit types of mixers which makes it possible to utilize more fully and eiiiciently the load carrying capacity of the trucks on which such mixers are mounted.

Another object of the invention is to provide a new and improved driving arrangement for concrete mixers which is particularly suitable for use in mixers of the transit ty e.

pOther and further objects of the invention will be apparent from the following description and claims and may be understood by reference to the accompanying drawings, of which there are six sheets, which by way of illustration show preferred embodiments of the invention and what I now consider to be the best mode in which I have contemplated applying the principles of my invention. Other embodiments of the invention may be used without departing from the scope of the present invention as set forth in the appended claims.

In the drawings:

Fig. l is a side elevational view of a concrete mixer of the transit type embodying my invention;

Fig. 2 is a side elevational view of the engine and transmission assembly;

Fig. 3 is an enlarged fragmentary sectional view of the transmission showing the forward and reverse transmission assembly and the main clutch;

Fig. 4 is a sectional view of the nal reduction stages of the transmission assemblyrand the driving relationship thereof with the mixer drum',

Fig. 5 is an enlarged cross sectional view through the transmission and taken generally along the line 5-5 of Fi .3'

Fig 6 is an enlarged fragmentary sectional view taken generally along the line 6--6 of Fig. 3;

Fig. 7 is a fragmentary side` elevational view of the side of the transmission opposite that shown in Fig. 3 and showing the operating controls for the transmission;

Fig. 8 is a fragmentary plan View taken along the line 8-8 of Fig. 7; and

Fig. 9 is a fragmentary sectional view of a modification showing the drive arrangement when the mixer drum is driven from the engine of the vehicle rather than from a separate engine as shown in Figs. 1 and 2.

As shown in Fig. l, a transit mixer type of concrete mixer embodying my invention consists in general of a mixer drum 20 supported for rotation about an upwardly inclined axis, an engine or motor 22 operatively connected to the mixer for rotating the same, a charging and discharging arrangement including a hopper 24, a funnel or spout 26, and a distributing chute 28, all mounted upon a frame 30 which as shown is mounted upon the chassis of a truck, The drum 20 may be of the type having a circular opening at its rear end and through which opening the drum is charged with materials to be mixed by means of the hopper 24. Such opening in the drum also permits discharge of the material, upon rotation of the drum in one direction, into the funnel 26 which discharges the mixed material into the distributing chute 28, which in turn delivers the material to the desired location.

The circular opening in the rear of the drum which is concentric with the axis of rotation thereof is provided with an annular closure 32 adapted to be moved between its open and closed positions by hand wheel 34. The hopper and closure arrangement for the drum may be in accordance with the disclosure of my copending application Serial No. 267,659, led January 22, 1952, for Mixer Closure, now Patent No. 2,639,128 dated May 19, 1953. The end of the hopper projects through the annular closure 32 and into the drum through the aforesaid opening in the rear end thereof.

The drum 2i) adjacent the open end thereof is provided with a cylindrical track 36 which rolls upon a pair of spaced rollers 38, the rollers 3S being journaled on an opstanding part 40 of the frame and being arranged at the sides of the mixer so as to form a cradle which rotatably supports the open or charging and discharging end of the drum 2t) for rotation about its axis.

The front or closed end of the drum 20 is rotatably supported on the transmission 42. The variable speed motor 22 of the internal combustion engine type is mounted on and supported by the frame 30 and drivingly connected through transmission 42 to the mixer drum for rotating the same, the transmission including provisions whereby the motor 22 may selectively rotate the drum about its axis in either direction. Rotation of the drum in one direction will function to mix the materials charged into the drum, while rotation of the drum in the opposite direction will function to elfect the discharge of materials from the drum into the spout 26.

The transmission 42 comprises a plurality of main sections, the housings 62, 64 and 66 of which are detachably bolted together. An annular ilange 68 on the housing 64 is bolted to the ywheel housing 70 of the engine 22, and the transmission 42 may be mounted on and supported by the frame 3i) in any suitable manner. The engine is provided with a series of legs 72 which rest upon a motor pallet 60, and blocks 58 of resilient material are arranged between pallet 66 and frame 30 for supporting motor 22 on frame 30. The motor 22 and transmission 42 thus comprise a motor drive unit on which the mixer drum 2i) is rotatably mounted. The transmission and its connection to the engine 22 and to the mixer drum 2t) are more fully disclosed in Figs. 3 and 4.

The transmission housing 64 is detachably bolted to the flywheel housing 70 of the engine and so that the main shaft of the transmission may be directly coupled to the ilywheel 82 of the engine by means of coupling members 84 and 86 so that the shaft 80 will turn with the crank shaft of the engine. The transmission further includes a planetary type of forward and reverse gear indicated generally at 88 which is housed within the transmission housing 66. As the housing 66 is detachably bolted to the housing 64, removal of the housing 66 will permit convenient access to the reverse gear 88. A water pump indicated generally at 90 is mounted on the end of the housing 66 and is directly coupled to the shaft 80 by llexible coupling 92. The pump 90 may be of the centrifugal type and since its impeller is. coupled directly to the shaft the pump will be driven at all times during engine operation.

The inlet 96 of the pump 90 is connected by conduit 98 to the bottom of the water tank 50, and the discharge 160 of the pump is connected to conduit 102 which extends to the inside of the mixer drum 29 for supplying the water for mixture with the materials supplied thereto through the hopper 24. The housings 62, 64 and ,66, since they are rigidly secured together, form a complete housing unit.

The iinal drive gear 104 of the reverse gear is arranged to drive gear 106 which forms part of a gear train, the gear train further including (Fig. 4) gear 198, shaft 110, gear 112., bevel gear 114, shaft 116, gear` 118 and gear 120, the gear 120 being splined on hollow shaft 122 which in turn is journaled in bearings 12d. The teeth of gear 126 formed integrally with the shaft 122 mesh with 'the teeth of three gears 126 spaced uniformly about the gear 126, each of the gears 128 being journaled on a shaft 130 mounted in the housing 62. an internal gear 132 mesh with the teeth of the gears 128 so as to be driven thereby, the gears 126, 12S and 132 providing the final gear reduction of the drive between the engine and the mixer drum. Since there are three gears 12S for transmitting the load from the gear 126 to the internal gear 132, it will be evident that each of the gears 128 carries only one-third of the load, and because of this the pressure on the teeth of the gears 126, 125 and 132 will be only a fraction of what the total pressure would be if only one gear such as 123 were employed.

The gear 132 is fixedly secured to a rotary plate 134 having its hub splined onto drive shaft 136 which is journaled in bearings 138 and 1450 suitably mounted in the transmission housing 62, the gears 126, 128 and 132 providing the nal speed reduction for drive shaft 136. The bearings 138 and 14@ support the shaft 136 for rotation with plate 134.

A coupling member 142 has a splined connection with shaft 136 for rotation therewith, and is secured on the end of shaft 136 by a plate 144 secured to shaft 136 by a series of bolts 146. Coupling member 142 has a spherical peripheral surface 14S shaped to lit and seat against similarly shaped inner peripheral surfaces 149 and 150 formed on a coupling means which comprises drum supporting plate 151 and a plate 152 bolted thereto. Coupling member 142 is provided with teeth 153 on its outer periphery arranged to mesh with the teeth 154 formed on the inner periphery of a ring 155 which is clamped between plates 151 and 152 by a series of bolts 156. The end wall 157 of drum 20 is rigidly bolted or riveted to supporting plate 151, whereby rotation of shaft 136 will rotate drum 20 about its axis.

The coupling member 142, ring 155, and supporting plates 151 and 152 provide a universal joint between shaft 136 and drum 2t?, thereby permitting the drum to shift relative to the axis of shaft 136 without subjecting the shaft to excessive strains. Since the discharge end of drum 26 is gravitationally supported for rotation on rollers 38, the drum, when the truck is moving over rough roads, has a tendency to bounce on rollers 38, and the universal joint connection between the drum and the transmission drive shaft will permit such movement of the drum and will compensate for slight disalignment of drive shaft 136 and the axis of the drum. The teeth 153 and 155% of coupling member 142 and ring 155 may be suitably formcd te permit some axial disalignment of drum 20 and shaft 136, and movement of the socket formed by plates 151 and 152 about the spherical surface of coupling member 142. The universal coupling is arranged outside the drum but inwardly of the plane of the end wall of the drum whereby the transmission housing 62 may be positioned closely adjacent the end wall of the drum. The internal gear 132 provides a part of the housing 62 of the transmission, and also forms a part of a housing for the universal joint.

A shield 15S of resilient material secured to plate 1'34 The teeth of and contacting supporting plate 151 provides a seal for the universal joint to prevent foreign material from entering the same. A plate 159 is detachably secured to plate 152 by bolts 160, to complete the universal joint housing. ,/tn oil seal 161 is secured to a flange 162 of housing 62 and sealingly engages the .outer periphery of internal gear 132 to prevent escape of lubricant from housing 62.

The load of the closed end of the drum is taken through the shaft 136 on the bearings 138 and 146, which in turn are supported by the transmission housing 62. The hub portion of plate 134 seats against the inner race of bearing 13S to take the axial thrust of the drum in one direction, and a nut 163 secured ,on the end of shaft 136 reacts against bearing 140 to take the axial thrust in the other direction. It will thus be evident that the drum 20 is, as previously described, rotatably mounted on the transmissien unit for rotation thereby about the axis of the drum.

The interior of the transmission housing is supplied with oil for lubricating the gears, shafts and bearings thereof, and since such rotating parts are wholly enclosed and running in lubricant, they will be protected against wear caused by grit, dirt, and the like.

It will be observed that all of the rotating, torque transmitting parts which provide the driving connection between the engine and the mixer drum are mounted in suitable bearings. The reverse gear unit 3 is of the type adapted to provide a forward, reverse and neutral driving relation between the engine and the mixer drum. That is, in neutral the engine can be operating without the mixer drum turning, Whereas in forward position the drum will be rotated in one direction while when the transmission is in reverse the drum 20 will be rotated in the opposite direction.

The reverse gear unit is of the planetary type which includes a planet carrier 164 which carries two sets of planet gears, one of the sets comprising the three gears 165 and the other set comprising the three gears 166. A brake indicated generally at 167 .is cooperable with the planet carrier 164 so as to hold the same against rotation, in which case the drive from the shaft 80 will be through sun gear 168 which is splined on the shaft S0, planet gears 165, planet gears 166, and sun gear 17). Sun gear 170 is formed integrally with the final drive gear 104 which meshes with the gear 106 previously described. The drive provided through the planet gears when the brake 167 is holding the carrier 164 against rotation will turn the gear 104 in the direction opposite to that of the shaft 8G and at substantially the same speed. When the transmission is in neutral the brake 167 will be released.

The reverse gear unit 88 also includes a multiple disc type of clutch indicated generally at 172, certain of the discs thereof being keyed to the planet carrier 164 for rotation therewith, While alternate discs are keyed to the clutch member 174 which is splined to the shaft 80. '111e controls for the clutch 172 and the brake 167 are such that when the brake 167 is engaged the clutch 172 is released, and vice versa. In neutral both the clutch and the brake are released. When the clutch 172 is engaged, the planet carrier 164 will rotate with the shaft 80, and the planetary gears 165 and 166 will thereby be locked up, as a result of which the entire planet carrier and gears carred thereby and clutch 172 will rotate as a unit, thereby driving the gear 1'70 and the gear 104 inthe same direction as the shaft 80 and at the same speed.

The clutch 172 is normally engaged by the springs 176 thereof and is adapted to be released by the clutch throwout collar 178 which is slidable on the hollow shaft 180, the collar 178 being engageable with a series of clutch release levers 182 which retract the pressure plate 184 of the clutch against the force of the springs 176. A clutch release yoke 186 mounted on rock shaft 183 is cooperable with the throwout collar 178 'for disengaging Lhe clutch 172 and holding it in its disengaged position. As the structure of the clutch 172 and its operation are conventional, it is believed that the foregoing description thereof will suce.

The rock shaft 188 projects from housing 66 and externally thereof is provided with an operating arm 190 (Fig. 7) having a roller 192 on the end thereof. The roller 192 is engageable with a cam 194 mounted on a rock shaft 196, the shaft 196 having an operating lever 198 secured thereto so that the cam 194 may be moved to its various positions for engaging and disengaging the clutch 172. A rod 200 pivotally connected at one end to the arm 198 and at its other end to a cam 202 provides a means whereby the lever 198 may control the engagement and disengagement of the brake 167, the arrangement being such that in neutral position both the clutch and the brake are disengaged; when the clutch 172 is engaged the brake is disengaged; and when the brake 167 is engaged the clutch 172 is disengaged. The lever 198 and the parts are as shown in Figs. 3, 6 and 7 in the engaged position of the clutch. Movement of the lever 198 to the left (Fig. 7) to a point where the roller 192 is on the high point of the cam 194 will move the arm 190 clockwise to disengage the clutch, and the reverse gear 88 will then be in neutral. Further movement of lever 198 in the same direction will function to apply the brake 167. Suitable indicating means are associated with the levers 198 and 190 so as to indicate the forward, neutral and reverse positions and to hold the operating controls in such positions.

When the lever 198 is operated to apply the brake 167 the rise 203 of the U-shaped cam 202 which is pivotally secured by pin 204 to the head 206 of the'shaft 208 will cause the brake applying members 210 and 212 to react on the lugs 214 secured to the ends of the brake band 215 and tighten the same on the drum 216 defined by the outer cylindrical surface of the planet carrier 164.

The brake is shown in its released position in Figs. 54

and 8.

In the modification shown in Fig. 9, instead of having a separate motor 22 for driving the mixer drum, the transmission through which the drum is driven is constructed and arranged so that it may be driven through a power take-off arrangement from the main drive system. For this purpose the transmission as shown in Fig. 9 is provided with a sprocket 300 adapted to be driven by a double chain (not shown) driven in turn from a sprocket of the power take-oit (not shown). Sprocket 300 is mounted on drive shaft 302 to which bevel gear 304 is secured. The teeth of bevel gear 304 in turn drive bevel gear 306 mounted on shaft 80 so that the shaft 80 instead of being directly coupled to the ywheel of the engine, as shown in Fig. 3, is driven through the bevel gear arrangement as shown in Fig. 9 by the chain and sprocket drive and the power take-0E from the mainl driving engine of the vehicle. The reverse gear for this modification is the same as that shown in Fig. 3.

Since in the modification shown'in'Fig. 9 the mixer drum will be driven from the main engine of the vehicle, there preferably is included in the transmission as shown in Fig. 9 a two-speed driving arrangement, and for this purpose a gear 308 is mounted on thel final drive gear 310 of the reverse gear unit 88, the gear 310 corresponding with the gear 104. The two-speed transmission of Fig. 9 includes a shaft 312 having a gear 314 splined thereto for rotation therewith, the teeth of gear 314 being in mesh with the teeth of gear 108 which drives the shaft 110 and the bevel gear 112. The bevel gear 112 as shown in Fig. 9 is the same as that shown in Fig. 4, and the rest of the transmission and the driving connection to the mixer drum 20 is as shown in Fig. 4.v

In Fig. 9 the transmission housing 66, instead of being bolted to the housing 64 as shown in Fig. 3, is bolted to the housing 315 of the two-speed transmission, and the housing 316 of the miter gear drive is secured to the housing 315. The housing 315 in turn is secured to the housing 62, all of the housings being rigidly secured together by any suitable detachable means,

'The two-speed transmission includes a gear cluster having gears 318 and 320 which as shown in Fig. 9 are in neutral position. When the teeth of the gear 320 are meshed with the teeth of gear 308 a high speed drive will be provided between the reverse gear 88 and the shaft 312, whereas when the teeth of the gear 318 are in mesh with the teeth of the gear 322 a low speed drive will be provided. The gear 322 is driven with the gear 310. Suitable conventional shifting means may be provided for shifting the gear cluster 318 and 320 between its various positions.

The operating controls for the transmission as shown in Fig. 9 will otherwise be the same as those shown in the first modification, except Vthat an additional control for the two-speed transmission of Fig. 9 will be necessary. In the previous modification the engine 22 of course is provided with suitable means for operating the throttle so that the speed of operation thereof may be regulated, thereby to drive the drum 20 at the desired speed. In the case of Fig. 9 the conventional throttle control for the main engine of the vehicle will be employed together with the two-speed transmission shown in Fig. 9 for driving the mixer drum at the desired speed.

The transmission as shown in Fig. 9 coupled with the remainder thereof as shown in Fig. 4 forms a unit which is suitably mounted on the frame 30 as in the previous modification, and in the modification as shown in Fig. 9 the mixer drum 20 again has a universal joint connection with the drive shaft 136 of the transmission.

While I have illustrated and described preferred embodiments of my invention, it is understood that these are capable of modification and I therefore do not wish yto be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A supporting and driving arrangement for the mixing drum of a concrete mixer comprising, a transmission adjacent one end of said drum including a housing and a driving member projecting from said housing toward the end wall of said drum, coupling means secured to said drum and wall concentric with the drum axis, said coupling means defining a spherical socket disposed entirely within the contines of said drum but sealed therefrom and said driving member projecting into said socket, a coupling member driven by said driving member and cooperable with said socket to provide a universal coupling between said driving member and said drum, and means providing a driving connection between said coupling member and said socket for drivingly connecting said driving member and drum.

2. A supporting and driving arrangement for the mixing drum of a concrete mixer comprising, means for supporting one end of said drum for rotation about its axis, a transmission at the other end of said drum including a housing and a driving member projecting from said housing toward the end wall of said drum, said end wall of said drum having an axial opening therein, coupling means secured to said drum end wall within said opening, said coupling means defining a socket concentric with the drum axis and exteriorly of said drum, a coupling member driven by said driving member and cooperable with said socket to provide a universal coupling between said driving member and said drum, and sealing means interposed between said driving member and said drum outwardly of said socket for sealing said universal cou- Y pling from the exterior.

3. Apparatus according to claim 2 wherein said universal coupling is arranged inwardly of said drum relative to the plane of the end wall of said drum and said transmission housing is positioned closely adjacent said end wall of said drum.

4. A supporting and driving arrangement for the mixing drum of a concrete mixer comprising, a transmission adjacent one end of said drum including a housing and a driving member projecting from said housing toward the end wall of said drum, coupling means secured to said drum end wall concentric with the drum axis, said coupling means including a socket disposed exteriorly of said drum but inwardly of the plane of said end wall of said drum, a coupling member driven by said driving member and cooperable with said socket to provide a universal coupling between said driving member and said drum, and means interposed between said drum and said driving member outwardly of said socket for sealing said universal coupling from the exterior.

5. Apparatus according to claim 4 including means providing a sealing between said driving member and the exterior.

6. A concrete mixer comprising, a mixer drum having provisions lat one end for charging and discharging the same, a supporting frame, means on said frame for supporting said end of said `drum for rotation about its axis, a transmission having one end supported by said frame atthe other end of said drum and including a housing and a driving member projecting from said housing toward the end wall of said drum, the end wall of said drum having coupling means secured thereto concentric with the drum axis and extending into said drum to define a socket disposed entirely within the contines of said duim, said driving member projecting into said socket and having a coupling member secured thereto and cooperable with said socket and drivingly engaging said coupling means to provide a universal joint connection between said driving member and said drum, and a motor mounted on said frame and connected to the other end of said transmission for supporting the same and driving said drum through said transmission.

7. A concrete mixer comprising, a mixer drum having provisions at one end for charging and discharging the same, a supporting frame, means on said frame for supporting said end of said drum for rotation about il's axis, a transmission mounted on said frame at the other end of said drum and including a housing and a driving member projecting from said housing toward said drum, said transmission including speed reduction and reversible drive power transmission mechanism drivingly connected to said driving member, the end wall of said drum having coupling means secured thereto and located entirely within the contines of said drum, a coupling member secured to said driving member and cooperable with and drivingly connected to said coupling means to provide a universal joint connection between said driving member and said drum, said speed reduction mechanism including an internal gear mounted on said driving member for driving the same and providing a part of the wall of said transmission housing.

8. A concrete mixer according to claim 7 including sealing means between said internal gear and saidhousing for scaling between the interior and exterior of said housing,

9. A concrete mixer according to claim 7 including -8 sealing meansbetween said transmission housing and said drum and disposed radially outwardly of said universal joint for sealing said universal joint from the exterior of said drum.

10. A supporting and driving arrangement for the mixing drum of a concrete mixer comprising, a transmission adjacent one end of said drum including a housing and a vdriving member projecting from said housing toward the end wall of Asaid drum, a pair of drum supporting plates secured to said drum end wall concentric with the drum axis and having complementary spherical surfaces formed ,thereon to provide a spherical socket, a couplingmember driven by said driving member and disposed within said socket, and a driving ring clamped between said socket forming plates and engageable with said coupling member for drivingly connecting said drum and driving member and providing a universal coupling between said driving vmember `and ,said drum.

ll. A supporting and driving arrangement for the mixing drum of a concrete mixer comprising, a transmission adiacent one -end of said drum including a housing and adriv'ing member projecting from said housing toward the end wall of said drum, an internal gear driven through said transmission and forming a Wall oi" said housing and mounted on said driving member for driving the same, sealing means between said internal gear and said housing for providing a seal between the interior and exterior of said housing, coupling means secured to said drum end wall concentric with the drum axis and deining a spherical socket into which said driving member projects, a ,coupling member driven by said driving member and cooperable with said socket to previde a universal coupling between said driving member and said drum, and means providing a driving connection between said coupling member and said socket for drivingly connecting said driving member and drum.

l2. Apparatus according to claim 11 including a motor connected to said transmission for driving the same and wherein said internal gear provides a nal speed rednetion for said-driving member.

13. Apparatus according to claim l1 including sealing means between said internalgear and said drum and disposed exteriorly of said socket for sealing said universal coupling from the exterior.

References Cited in the file of this patent UNITED STATES PATENTS 2,451,555 Hilkemeier et al. Oct. 19, 1948 2,487,485 Smiley Nov. 8, 1949 2,511,240 Bohmer June 13, 1950 2,563,336 Jaeger Aug. 7, 1951 FOREIGN PATENTS 587,826 Great Britain May 7, 1947 

